Various inverter-integrated electric compressors with which an inverter is integrated have recently been proposed as compressors for air conditioners installed in vehicles. These inverter-integrated electric compressors are configured such that an inverter accommodating section (an inverter box, a case, an outer frame, or the like) is provided on the periphery of a housing that accommodates an electric motor and a compression mechanism, and an inverter that converts DC power supplied from a high-voltage power supply to three-phase AC power and feeds the three-phase AC power to the electric motor through glass-sealed terminals is installed in the inverter accommodating section, so that the rotational speed of the compressor can be variably controlled in accordance with the air conditioning load.
The inverter includes an inverter circuit section composed of a power system board (including a base, a unit base, etc.) on which a plurality of semiconductor switching devices (for example, IGBTs) that convert DC power to three-phase AC power are mounted and a CPU board (printed board) on which a control and communication circuit having a device that operates at low voltage, such as a CPU, is mounted; and high-voltage-system components, such as an inductor coil and a smoothing capacitor, which are provided on a high-voltage line for supplying DC power supplied from the high-voltage power supply to the inverter circuit section to reduce the switching noise and current ripples of the inverter.
In such inverter-integrated electric compressors, the inverter circuit section and the high-voltage-system components that constitute the inverter, such as an inductor coil and a smoothing capacitor, are in general accommodated together in the inverter accommodating section (an inverter box, a case, an outer frame, or the like) provided on the periphery of the housing and integrated into one unit (for example, see Patent Literatures 1 and 2). This is for the purpose of making the inverter-integrated electric compressor as compact as possible in consideration of the ease of mounting on vehicles.